178 ERNEST A. BACK. 



blackish. Entire legs, including coxae, whitish pruinose; the coxae 

 most densely so, the femora and hind tibiae the least; the tibiae with 

 short sparse pile and, together with the tarsi, with longer white out- 

 standing bristles, arranged somewhat as in Townsendia n-iger, but on 

 the tarsal segments situated nearer the tip. Claws reddish at base; 

 pulvilli normal, pale. Wings hyaline, violescent, slightly darkened by 

 the omnipresent microscopic pubes; attenuated at base, allulae want- 

 ing; but four posterior cells present, the vein separating the third and 

 fourth posterior cells being gone; anal cell closed and petiolate; the 

 anterior cross-vein much nearer the base than the apex of the discal 

 cell. 



Type. — American Museum. A single female. 



J/a6^/a^— Montopolis, Travis Co., Texas, May 1, 1903 (W. 

 M. Wheeler). 



I have called this species pulcherrima because of the white 

 pruinose spots of the dorsum and vertex v^hich in certain 

 lights appear most beautiful under the compound microscope. 

 It is out of place in this genus because of its antennae, but at 

 present I know of no better place to put it. Aside from the 

 antennas, it agrees very well with the generic description of 

 Townsendia. 



ABLAUTUS. 



Ahlautiis Loew, Cent., VII, 63, 1866. 



Ablautatus Loew, Berl. Ent. Zeit., 1874, 377. 



Ablautus Schiner, Verh. Zool.-Bot. Ges., XVI, 847, 1866; quotes 



orig. desc. 

 Ablautatus Osten Sacken, West. Dipt., 289, 1877. 

 Ablautus Williston, Manual 1896, 54; adopts orig. form. 



Small to rather medium-sized species easily recognized by 

 the large claws and entire absence of pulvilli, peculiar arrange- 

 ment of bristles on dorsum of thorax and legs, and the brushes 

 on the last three segments of the front tarsi of the male. 



Face and front comparatively narrow; face almost flat, 

 without gibbosity, with a dense mystax reaching nearly or 

 quite to the antennas ; front very little broader above ; vertex 

 but little depressed, the ocellar tubercle large and bearing a 

 conspicuous tuft of hair and bristles; occiput with numerous 

 bristles. Antennae short; basal segments short, subequal, 

 below clothed with conspicuous bristles, some of which often 

 are half as long as the antennas, on the upper side with shorter 



